Electric toaster



inventio'rirrelates 't elc .y y

,andthe object ofour'invention i toprovide im? 4provedlheatingfunitsiforsuch devices which shall be .moreeiiicient inoperation, morefdurable in usevj '1 iFig. 1 'isH a 'front elevationalview par Patented May 1, 1934 tly in se'ction, showing a bread toasterembodying our im. proved heating unit, and

Fig. 2 is a sectional view taken on lines 2-2 of Fig. 1.

Fig. 3 shows a front elevation of a heating unit embodying our inventionin another form.

10 indicates the base of the toaster to which the vertical sideframe'members 11--11 respectively.

rare suitably attached, and 12 indicates the top of 'the toaster framesupported by the side frame members. Extending between the top and baseof the toaster frame are a plurality of guard wires 13-13 etc., againstwhich the bread slice to be toasted is inclined in the usual manner. Asis customary, the rear of the toaster frame is similarly provided withguard wires and is in all respects identical with the front so that twoslices of bread may be simultaneously toasted, one on either side of thetoaster frame.

Centrally positioned within the frame is an electrical heating unitcomprising upright supports 14-14, respectively, each of which is formedchannel shape from a single strip of conducting metal and crimped, as at15-15 etc., to holdopposite ends of the horizontally extending parallelstrips 16--16 etc.

The strips 16 must be of material which provides good insulation againstboth heat and electricity. Micaceous material is well suited andgenerally used in devices o! this class but is expensive in large piecesrelative to its cost per pound in pieces of small size. One of theeconomies of our construction resides in the employment of a pluralityof small pieces of such material.

The supports 14 are offset adjacent the base, as shown, and are held inposition by means of screw, nut and washer combinations, 17, insulatedfrom the base by bushings 18 of porcelain, mica, or other suitablematerial. These combinations 17 also serve as binding terminals for thelead wires 19, as` illustrated.

The supports M are similarly insulated and fastened at their upper endsto angular brackets 20, the brackets, in turn being riveted at 21 to theframe ytop 12.

Each of the strips 16 is evenly wound with flat toastersv irais-'lier a,different number of starnberg, ,www with alityy .f.;heating resistanceand heating capacity, being situated closest to the base of the toasterframe. 'This ar- 65 rangement is made to provide even toasting of thebread slice since the heat generated radiates upwardly and also becausethe -slice Ais upwardly inclined against the guard wires 13 and itslower end is therefore spaced from the heating unita greater distance,as will be readily understood."Agi

The wires 22 of the several heating elements are electrically connectedin series by conducting jumpers 23--23 and the upright supports 14`(Figs.

v1 and 2), the several connections being madeby 'I6 means of rivets24-24etc., which pass thru the micaceous strips 16 and also serve toreinforce the construction. Thus the current flowsfrom one of the leadwires 19 to one of the conducting uprights 14, thence thru the severalresistance wires 22, which are thereby suitably heated, and finallyreturns to the other lead wire 19 thru the opposite upright to completethe circuit.

It will be noted that the comparatively fragile wires 22 are notextended from their respective g5 strips 16 and that the onlyconnections between the heating unit and the/frame is by means of theupright supports 14. y

By employing separate resistance ribbons or wires 22 on theseveral-strips 16, a substantial 90 .economy is eiected in manufacturingthe heating unit, it being practicable to evenly wind the strips bymeans of a coil winding machine rather than by hand. This feature of theconstruction also permits of simple and inexpensive repair of theheating unit in case any one of the fragile resistance wires becomesbroken or burns out. This is done by replacing only one of the elementsor rewinding one of the strips with new ribbon.

It has been found that it is usual for only one of the wires'22 to burnout at a time, whether hecause .of an overload-of current or long use.Where it is desired to substituteian entire new heating unit for an oldone, such substitution may be more readily made than in other con- 106structions of this type.

In the modification of our invention shown in Fig. 3. verticallyextending micaceous strips 26-26 are substituted for .the uprights 14.The current flows from the terminal pole 27 thru the 110 resistancewires 22 wound on all of the strips, as shown, and returns to terminalpole 28, the wires being connected in circuit by rivets 29 which passthru the several strips to hold them in assembled position.

In this modication the elements are shown connected in the circuit inseries parallel, the current being divided at the junctures of thelowermost and intermediate lateral elements with the verticallyextending side strip elements. This construction permits the employmentof an even larger number of smaller micaceous pieces.

In either device, the heating unit comprisingv dierent heatingcapacities, said strips being supported adjacent their opposite ends bysaid conductors and arranged horizontally one above the other in theorder of their heating capacities, and means connecting said resistancewires in circuit with said conductors and with each other.

2. An electric heating unit adapted for use in a bread toasting devicecomprising upwardly extending `conducting means, a plurality ofnonconducting heat resisting strips each' having an uninsulatedresistance wire bf dierent length evenly wound thereon to provideseparate heating elements of diil'erent heating capacities, said stripsbeing supported adjacent their opposite ends by said means and arrangedhorizontally one above the other in the order of their heatingcapacities, and means connecting said resistance wires in -circuit withsaid conducting means and with each

